MI5 directly colluded in the savage ‘medieval’ torture in Morocco of Binyam Mohamed, the Guantanamo inmate who was last week released to live in Britain.

The revelation came as Mohamed broke his silence about the full horror of his seven years in detention in a compelling interview with The Mail on Sunday.

Documents obtained by this newspaper – which were disclosed to Mohamed through a court case he filed in America – show that months after he was taken to Morocco aboard an illegal ‘extraordinary rendition’ flight by the U.S. Central Intelligence Agency, MI5 twice gave the CIA details of questions they wanted his interrogators to put to him, together with dossiers of photographs.

At the time, in November 2002, Mohamed was being subject to intense, regular beatings and sessions in which his chief Moroccan torturer, a man he knew as Marwan, slashed his chest and genitals with a scalpel.

Mohamed, 30, who returned to Britain last month from Guantanamo Bay after seven years detained without charge, said that he reached his lowest ebb the moment he realised that Britain was conniving in his torture.

He said: ‘They started bringing British files to the interrogations – not one, but several of them, thick binders, some of them containing sheaves of photos of people who lived in London and places there like mosques.